The Apache project is an open source HTTP server for modern operating systems, including GNU-Linux and Windows. The goal of this project is to provide a secure, efficient, and extensible server that provides HTTP services in sync with current HTTP standards.
The essential function that a web server like Apache must perform is to display the web pages hosted on the server to the various browsers that request them. Its functionality can be extended through modules that support different technologies, making it compatible with any CMS.
Apache currently has a share of around 40% of the web servers used on the internet, closely followed by one of the fastest growing projects, nginx, which is better suited to high-performance environments.